The present invention relates to semiconductor devices, and more specifically, to a semiconductor device including a smooth epitaxial topology.
Semiconductor fabrication processes utilize epitaxially grown material (i.e., epi) such as silicon doped with phosphorus (Si:P) or silicon germanium (SiGe), for example, to merge source/drain regions of semiconductor fins formed on a semiconductor substrate. During conventional epitaxial growth processes, the epi forms as facets on the sidewalls of the semiconductor fins, and may continue to grow at different and non-uniform rates depending on the direction of growth. The non-uniform growth rate of the epi typically results in a rough (i.e., corrugated) epitaxial topology. The rough epitaxial topography, however, can affect diffusion contact (CA) landing regions and can increase the fringing capacitance between the CA and the polysilicon (PC) control gate.